| abstract |
A porous substrate having an average pore diameter of 20 nm or more and 100 nm or less, and a porous layer provided on one or both surfaces of the porous substrate and containing a polyvinylidene fluoride resin and a filler. Contains 45% by volume or more and 75% by volume or less of filler with respect to the total solid content, and the weight average molecular weight of the polyvinylidene fluoride resin contained in the porous layer is 1 million or more, A separator for a non-aqueous secondary battery, wherein the peel strength between the porous layer is 0.20 N / 12 mm or more. |